IIRC there's some lore that in passing mentions that it is very disadvantageous to be fighting a war from the bottom of the solar system's gravity well - which is a very valid question. Even relatively small asteroids turned into a kinetic weapon could be absolutely devastating, possibly orders of magnitude worse than nuclear weapons, and they are very difficult to both detect and stop

And aside from the catastrophic effects on earth, it would be even more effective to use them on (for example) human sites on Mercury or Mars, where you wouldn't need to worry about collateral and environmental damage

Is there a lore reason in-game for why the Hydra don't start adopting this tactic, particularly when humanity reveals itself to actually be a threat and able to fight the Hydra on terms approaching equality?